1. Field of the Invention
The present invention relates to a throttle device having a gear that connects a throttle shaft and a motor.
2. Description of the Related Art
In a conventional throttle device, as disclosed in Japanese Patent Application Laid-open No. 2007-23859, each of the throttle shafts provided in the two throttle bodies are fitted from the outside to a gear provided in a gear case disposed between the two throttle bodies.
The throttle device disclosed in the above Japanese Patent Application Laid-open No. 2007-23859 has problems including that the two throttle shafts are connected to a gear, but the structure of the connection of the two shafts to the gear is complex, and the rotational responsiveness of the throttle valves is poor due to the increase in weight. Also, to ensure the connection stiffness between the two throttle shafts and the gear, the external fitting portion of the gear to which the throttle shaft is fitted is made large, and as a result the size of the gear case must be made larger. When the space between the throttle bodies is reduced by making the gear case larger, it is necessary to provide the fitting portions for fitting the mating components in the throttle bodies in a location that projects from the gear case, so the overall length of the air intake pipes is lengthened. Therefore the capacity of the air intake pipe on the downstream side of the throttle valve from the throttle valve to the cylinder head becomes larger, and this has the problem that the engine responsiveness becomes poorer.